//
// Created by xuhuahai on 2017/4/24.
//

#include <ws/sha1.h>

#include <memory.h>


typedef uint32_t                u32;


/****************
* Rotate a 32 bit integer by n bytes
****************/
#if defined(__GNUC__) && defined(__i386__)
static inline u32 rol(u32 x, int n)
{
	__asm__("roll %%cl,%0"
		:"=r" (x)
		: "0" (x), "c" (n));
	return x;
}
#else
#define rol(x,n) ( ((x) << (n)) | ((x) >> (32-(n))) )
#endif

#define K1  0x5A827999L
#define K2  0x6ED9EBA1L
#define K3  0x8F1BBCDCL
#define K4  0xCA62C1D6L
#define F1(x,y,z)   ( z ^ ( x & ( y ^ z ) ) )
#define F2(x,y,z)   ( x ^ y ^ z )
#define F3(x,y,z)   ( ( x & y ) | ( z & ( x | y ) ) )
#define F4(x,y,z)   ( x ^ y ^ z )


#define M(i) ( tm = x[i&0x0f] ^ x[(i-14)&0x0f]    \
               ^ x[(i-8)&0x0f] ^ x[(i-3)&0x0f]    \
               , (x[i&0x0f] = rol(tm,1)) )


#define R(a,b,c,d,e,f,k,m)  do { e += rol( a, 5 ) \
            + f( b, c, d )                        \
            + k                                   \
            + m;                                  \
        b = rol( b, 30 );                         \
    } while(0)


void hash1_reset(SHA1_CONTEXT* hd)
{
    hd->bFinal = 0;
    hd->h0 = 0x67452301;
    hd->h1 = 0xefcdab89;
    hd->h2 = 0x98badcfe;
    hd->h3 = 0x10325476;
    hd->h4 = 0xc3d2e1f0;
    hd->nblocks = 0;
    hd->count = 0;
    memset(hd->buf, 0, 64);
}

/*
* Transform the message X which consists of 16 32-bit-words
*/
static void hash1_transform(SHA1_CONTEXT* hd, uchar *data)
{
    uint a, b, c, d, e, tm;
    uint x[16];

    /* get values from the chaining vars */
    a = hd->h0;
    b = hd->h1;
    c = hd->h2;
    d = hd->h3;
    e = hd->h4;

#ifdef BIG_ENDIAN_HOST
    memcpy(x, data, 64);
#else
    { int i;
        uchar *p2;
        for (i = 0, p2 = (uchar*)x; i < 16; i++, p2 += 4) {
            p2[3] = *data++;
            p2[2] = *data++;
            p2[1] = *data++;
            p2[0] = *data++;
        }
    }
#endif

    R(a, b, c, d, e, F1, K1, x[0]);
    R(e, a, b, c, d, F1, K1, x[1]);
    R(d, e, a, b, c, F1, K1, x[2]);
    R(c, d, e, a, b, F1, K1, x[3]);
    R(b, c, d, e, a, F1, K1, x[4]);
    R(a, b, c, d, e, F1, K1, x[5]);
    R(e, a, b, c, d, F1, K1, x[6]);
    R(d, e, a, b, c, F1, K1, x[7]);
    R(c, d, e, a, b, F1, K1, x[8]);
    R(b, c, d, e, a, F1, K1, x[9]);
    R(a, b, c, d, e, F1, K1, x[10]);
    R(e, a, b, c, d, F1, K1, x[11]);
    R(d, e, a, b, c, F1, K1, x[12]);
    R(c, d, e, a, b, F1, K1, x[13]);
    R(b, c, d, e, a, F1, K1, x[14]);
    R(a, b, c, d, e, F1, K1, x[15]);
    R(e, a, b, c, d, F1, K1, M(16));
    R(d, e, a, b, c, F1, K1, M(17));
    R(c, d, e, a, b, F1, K1, M(18));
    R(b, c, d, e, a, F1, K1, M(19));
    R(a, b, c, d, e, F2, K2, M(20));
    R(e, a, b, c, d, F2, K2, M(21));
    R(d, e, a, b, c, F2, K2, M(22));
    R(c, d, e, a, b, F2, K2, M(23));
    R(b, c, d, e, a, F2, K2, M(24));
    R(a, b, c, d, e, F2, K2, M(25));
    R(e, a, b, c, d, F2, K2, M(26));
    R(d, e, a, b, c, F2, K2, M(27));
    R(c, d, e, a, b, F2, K2, M(28));
    R(b, c, d, e, a, F2, K2, M(29));
    R(a, b, c, d, e, F2, K2, M(30));
    R(e, a, b, c, d, F2, K2, M(31));
    R(d, e, a, b, c, F2, K2, M(32));
    R(c, d, e, a, b, F2, K2, M(33));
    R(b, c, d, e, a, F2, K2, M(34));
    R(a, b, c, d, e, F2, K2, M(35));
    R(e, a, b, c, d, F2, K2, M(36));
    R(d, e, a, b, c, F2, K2, M(37));
    R(c, d, e, a, b, F2, K2, M(38));
    R(b, c, d, e, a, F2, K2, M(39));
    R(a, b, c, d, e, F3, K3, M(40));
    R(e, a, b, c, d, F3, K3, M(41));
    R(d, e, a, b, c, F3, K3, M(42));
    R(c, d, e, a, b, F3, K3, M(43));
    R(b, c, d, e, a, F3, K3, M(44));
    R(a, b, c, d, e, F3, K3, M(45));
    R(e, a, b, c, d, F3, K3, M(46));
    R(d, e, a, b, c, F3, K3, M(47));
    R(c, d, e, a, b, F3, K3, M(48));
    R(b, c, d, e, a, F3, K3, M(49));
    R(a, b, c, d, e, F3, K3, M(50));
    R(e, a, b, c, d, F3, K3, M(51));
    R(d, e, a, b, c, F3, K3, M(52));
    R(c, d, e, a, b, F3, K3, M(53));
    R(b, c, d, e, a, F3, K3, M(54));
    R(a, b, c, d, e, F3, K3, M(55));
    R(e, a, b, c, d, F3, K3, M(56));
    R(d, e, a, b, c, F3, K3, M(57));
    R(c, d, e, a, b, F3, K3, M(58));
    R(b, c, d, e, a, F3, K3, M(59));
    R(a, b, c, d, e, F4, K4, M(60));
    R(e, a, b, c, d, F4, K4, M(61));
    R(d, e, a, b, c, F4, K4, M(62));
    R(c, d, e, a, b, F4, K4, M(63));
    R(b, c, d, e, a, F4, K4, M(64));
    R(a, b, c, d, e, F4, K4, M(65));
    R(e, a, b, c, d, F4, K4, M(66));
    R(d, e, a, b, c, F4, K4, M(67));
    R(c, d, e, a, b, F4, K4, M(68));
    R(b, c, d, e, a, F4, K4, M(69));
    R(a, b, c, d, e, F4, K4, M(70));
    R(e, a, b, c, d, F4, K4, M(71));
    R(d, e, a, b, c, F4, K4, M(72));
    R(c, d, e, a, b, F4, K4, M(73));
    R(b, c, d, e, a, F4, K4, M(74));
    R(a, b, c, d, e, F4, K4, M(75));
    R(e, a, b, c, d, F4, K4, M(76));
    R(d, e, a, b, c, F4, K4, M(77));
    R(c, d, e, a, b, F4, K4, M(78));
    R(b, c, d, e, a, F4, K4, M(79));

    /* Update chaining vars */
    hd->h0 += a;
    hd->h1 += b;
    hd->h2 += c;
    hd->h3 += d;
    hd->h4 += e;

}


// Update the message digest with the contents of INBUF with length INLEN.
void hash1_write(SHA1_CONTEXT* hd, uchar *inbuf, uint inlen)
//static void sha1_write( SHA1_CONTEXT *hd, char *inbuf, uint inlen)
{
    if (hd->bFinal)
        hash1_reset(hd);
    if (hd->count == 64) { /* flush the buffer */
        hash1_transform(hd,hd->buf);
        hd->count = 0;
        hd->nblocks++;
    }
    if (!inbuf)
        return;
    if (hd->count) {
        for (; inlen && hd->count < 64; inlen--)
            hd->buf[hd->count++] = *inbuf++;
        hash1_write(hd, NULL, 0);
        if (!inlen)
            return;
    }

    while (inlen >= 64) {
        hash1_transform(hd, inbuf);
        hd->count = 0;
        hd->nblocks++;
        inlen -= 64;
        inbuf += 64;
    }
    for (; inlen && hd->count < 64; inlen--)
        hd->buf[hd->count++] = *inbuf++;
}

/* The routine final terminates the computation and returns the digest.
* The handle is prepared for a new cycle, but adding bytes to the
* handle will the destroy the returned buffer.
* Returns: 20 bytes representing the digest.
*/
void hash1_final(SHA1_CONTEXT* hd)
{
    uint t, msb, lsb;
    uchar *p;

    hash1_write(hd, NULL, 0); /* flush */;

    t = hd->nblocks;
    /* multiply by 64 to make a byte count */
    lsb = t << 6;
    msb = t >> 26;
    /* add the count */
    t = lsb;
    if ((lsb += hd->count) < t)
        msb++;
    /* multiply by 8 to make a bit count */
    t = lsb;
    lsb <<= 3;
    msb <<= 3;
    msb |= t >> 29;

    if (hd->count < 56) { /* enough room */
        hd->buf[hd->count++] = 0x80; /* pad */
        while (hd->count < 56)
            hd->buf[hd->count++] = 0;  /* pad */
    }
    else { /* need one extra block */
        hd->buf[hd->count++] = 0x80; /* pad character */
        while (hd->count < 64)
            hd->buf[hd->count++] = 0;
        hash1_write(hd, NULL, 0);  /* flush */;
        memset(hd->buf, 0, 56); /* fill next block with zeroes */
    }
    /* append the 64 bit count */
    hd->buf[56] = msb >> 24;
    hd->buf[57] = msb >> 16;
    hd->buf[58] = msb >> 8;
    hd->buf[59] = msb;
    hd->buf[60] = lsb >> 24;
    hd->buf[61] = lsb >> 16;
    hd->buf[62] = lsb >> 8;
    hd->buf[63] = lsb;
    hash1_transform(hd, hd->buf);

    p = hd->buf;
#ifdef BIG_ENDIAN_HOST
#define X(a) do { *(u32*)p = hd->h##a ; p += 4; } while(0)
#else /* little endian */
#define X(a) do { *p++ = hd->h##a >> 24; *p++ = hd->h##a >> 16; \
        *p++ = hd->h##a >> 8; *p++ = hd->h##a; } while(0)
#endif
    X(0);
    X(1);
    X(2);
    X(3);
    X(4);
#undef X
    //Hash1 operation finally
    hd->bFinal = 1;
}


uchar* hash1_get(SHA1_CONTEXT* hd)
{
    if (!hd->bFinal)
        hash1_final(hd);
    return hd->buf;
}

